Air distribution system for a bus



C. DAVIES AIR DISTRIBUTION SYSTEM FOR A BUS Filed Dec Jan. 9, 1968 INVENTOR. C'l/AQLES' DAV/E5 ATTORNEX United States Patent 3,362,317 AIR DISTRIBUTION SYSTEM FOR A BUS Charles Davies, Yonkers, N.Y., assignor to Wayne Cool- ABSTRACT OF THE DISCLOSURE Air distribution apparatus comprising elongated ducts at the underside of the top of the bus, each duct decreasing in cross-sectional area longitudinally, with air straightening means in each duct to cause the air to flow longitudinally within the duct and each duct having an air distribution portion provided with a plurality of spaced air outlet passages which increase in size from the inlet ends to the outlet ends whereby to convert velocity pressure of the air on the inlet side of said passages to substantially static pressure at the output side thereof to produce a lowering of speed of the air passing through said passages.

This invention relates to air distribution apparatus, and 7 more particularly to such apparatus for use in air conditioning systems for vehicles, particularly buses.

An object of this invention is to provide air distribution apparatus of the character described wherein the air will be distributed evenly throughout the space served by the apparatus, substantially without drafts.

Another object of this invention is to provide air distribution apparatus of the character described including improved diffuser means having means to convert the velocity pressure of the air on the duct side of the diffuser to substantially static pressure on the output side of the diffuser with a lowering of the speed of the air passing through the diffuser, by means of providing an outlet area of the diffuser which is larger than the inlet area of the diffusera Yet another object of thisinvention is to provide air distribution apparatus of the character described comprising straightening means interposed in the air duct and positioned upstream from an irregularly shaped portion of the duct to thereby prevent turbulence in the air stream in the duct downstream of said'irregularly shaped portion.

A further' object of this invention is to provide air distribution apparatus of the character described having improved duct area reducing means extending from the inlet end to the outer end of the duct, whereby to maintain air speed substantially constant over the entire length of the duct despite the constantly decreasing volume of air in the duct from said inlet to said outer end.

Still another object of this invention is to provide air distribution apparatus of the character described which shall be economical to manufacture and install, which shall be pleasing in appearance, which shall have no moving parts, which may be adapted for use in existing systems, and which shall be practical and efficient to a high degree in use.

Other objects of this invention will in part be obvious and in part hereinafter pointed out.

The invention accordingly consists in the features of construction, combinations of elements, and arrangement of parts which will be exemplified in the construction hereinafter described, and of which the scope of invention will be indicated in the following claims.

In the accompanying drawing, in which is shown an illustrative embodiment of this invention,

FIG. 1 is a horizontal cross-sectional view through a vehicle duct system embodying the invention;

FIGS. 2, 3 and 4 are vertical cross-sectional views taken .on lines 2-2, 3-3 and 4-4, respectively, of FIG. 1;

FIG. 5 is a cross-sectional view taken on line 5-5 of FIG. 4; and

FIG. 6 is an external elevational view looking in the direction of arrows 6-6 of FIG. 4.

Referring now in detail to the drawing, 10 designates an air distribution apparatus embodying the invention mounted on the ceiling of the passenger compartment of a usual transit bus. A portion of the floor F of the vehicle is shown in FIG. 1. Apparatus 10 comprises a left side air distributing duct 11, and a right side air distributing duct 12. Ducts 11 and 12 have inlet ends 13 and 14, respectively, which connect the ducts to either or both the heating and air conditioning systems of the bus. Ducts 11 and 12 extend from the rear of the bus, substantially the full length thereof, to just short of the front thereof.

Ducts 11 and 12 are symmetrically disposed on either side of the longitudinal, vertical, center plane of the bus, and are similar in configuration throughout their lengths. Duct 12 comprises an inner, short vertical wall portion 15, an inner outwardly and downwardly sloped wall portion 16 extending from the lower end of portion 15, a relatively large radius curved wall portion 17 joined at its inner end to portion 16, and an outer, long vertical wall portion 18 joined at its lower end to portion 17. The upper ends of wall portions 15 and 18 are'substantially coplanar, and any suitable means, not shown, are provided to attach these ends to the ceiling or top C of the bus. Thus, ceiling C closes the top, open end of each duct to form a sealed air pipe or conduit therewith. Duct 12 also comprises a front end wall 19 to close the front end of the duct. Wall 19 may be perforated or formed with any usual grill or the like. Duct 11 is composed of wall portions similar to those described above, and similar parts are indicated by the same reference numeral followed by a. j

Interposed in duct 12, at a point about one-third along its length from inlet 14, is a duct portion 20 which is positioned over the usual rear exit door of the bus. Portion 26 comprises a flat center wall portion 21 at a greater level than adjacent parts of the duct and provided with a grill, diffuser or register 22 of any usual construction at the outer end thereof positioned over the rear exit door of the bus to allow for head room for passengers leaving the bus. The duct portion 20 is extended outwardly of the duct so as to maintain substantially required crosssectional area. Wall portion 20 is joined to duct 12 by front and rear funnel-like connecting wall portions 23 and 24 respectively. Reference may be had to FIGS. 1 and 9 of co-pending application Ser. No. 349,080, filed Mar. 3, 1964, and entitled Air Conditioning Apparatus for Vehicles, Especially for Buses, for other views of duct portions 20, 23 and 24.

Means are provided to prevent turbulence in the air in duct 12 as it passes through portion 20 and therebeyond. To this end an air straightener 30 is positioned in and fills duct 12 where it joins rear connecting duct portion 24. Air straightener 30 comprises a honeycomb of intersecting vertical Walls 31 and horizontal walls 32 forming a plurality of relatively small passages 33 disposed parallel to the desired direction of air flow in duct 12. Straightener 30 may be made of plastic or any other suitable material.

Ducts 11 and 12 include diffusers or grills mounted in suitable openings 51 in Wall portions 18a and 18 to allow the air in the duct to move from the duct to the passenger compartment of the bus. Diffusers 50 extend over the whole length of wall 18a, and the whole length of wall 18 except at portion 20 and the area of straightener 30. Diffusers 50' comprise top support members 52 secured to wall portions 18 and 18a at the upper end of openings 51 and 51a, and lower support members 53 secured to wall portions 18 and 18a at the lower end of openings 51 and 51a. Secured between members 52 and 53 are a plurality of spaced vane or nozzle forming members 54. Members 54 are triangular in cross-section. Their crosssection may be an equilateral triangle. One flat side of each member 54 faces into the duct, and the opposite apex faces outwardly. Thus, the space between each two members 54 increases, moving from within the duct to without the duct. This increasing outlet area changes the velocity pressure of the air moving therethrough to almost static pressure with a lowering of speed, and produces a uniform, draft-free distribution of air within the bus. Members 54 may be of any suitable material such as sheet metal, plastic, metal, or the like.

Means are provided to progressively reduce the crosssectional area of the duct over its length, to compensate for the progressively decreasing volume of air in the duct from rear to front as the air is distributed, to obtain an even air distribution pattern throughout the bus. To this end a straight, flat plate member 60 extends from a position at the rear end of duct 11 where it contacts wall portion 15, to end wall 19a to which it is joined at a point in spaced relation to wall portion 18a. The space between member 60 and wall portion 15a is unused. A member 65 similar to member 60 is provided in duct 12. Member 65 cuts through straightener 30. The space between member 65 and wall portion 15 is a dead or unused space.

It will thus be seen that there is provided an article and apparatus in which the several objects of this invention are achieved, and which is well adapted to meet the conditions of practical use.

As possible embodiments might be made in the above invention, and as various changes might be made in the embodiment above set forth, it is to be understood that all matter herein set forth or shown in the accompanying drawings, is to be interpreted as illustrative and not in a limiting sense.

I claim:

1. An air chamber for receiving a flow of air, said chamber comprising a longitudinally extending duct having a side wall provided with an air distributing portion, said portion comprising means providing a plurality of spaced air outlet passages separated by imperforate air blocking portions so that air can only pass through said passages, said passages increasing in size from the inlet ends to the outlet ends of said passages, said means comprising a plurality of members, each of said members being of triangular cross-section throughout and disposed with one flat surface facing into said chamber and with a pair of symmetrical flat divergent surfaces inclined to said first mentioned flat surface, said members being disposed transversely of said duct, and means in said duct to straighten the flow of air in said duct longitudinally of said duct, said straightening means comprising a honeycomb of intersecting vertical walls and horizontal walls forming a plurality of relatively small passages disposed parallel to the direction of air flow in said duct.

2. An air chamber for receiving a flow of air, said chamber comprising a longitudinally extending duct having a side wall provided with an air distributing portion, said portion comprising means providing a plurality of spaced air outlet passages separated by imperforate air blocking portions so that air can only pass through said passages, said passages increasing in size from the inlet ends to the outlet ends of said passages, said means comprising a plurality of members, each of said members being of triangular cross-section throughout and disposed with one fiat surface facing into said chamber and with a pair of symmetrical flat divergent surfaces inclined to said first mentioned flat surface, said members being disposed transversely of said duct, in combination with the top of a bus, said duct being located at the underside of said top of said bus running the length of the bus, and said air distributing portion being located at a longitudinal side of said duct, said bus having a rear door and said duct having an intermediate widened and flattened portion located over said door the bottom Wall of said intermediate portion being at a greater elevation than the bottom wall of adjacent parts of said duct, an air grill on the bottom wall of said widened and flattened portion, and an air straightener in said duct adjacent the entrance end of said widened and flattened portion.

3. The combination of claim 2, and said air grill extending substantially the length of said bottom wall of said widened and flattened portion.

4. The combination of claim 2, and said duct at least for a portion of the length thereof decreasing in crosssectional area lengthwise of said duct in the direction of the flow of air therethrough.

References Cited UNITED STATES PATENTS 1,440,781 1/ 1923 Joesphs et a1. 9840 1,506,904 9/1924 Harrison 98--40 1,592,718 7/ 1926 Browne 9840 1,725,888 8/1929 Quinn 98-40 X 2,251,617 8/1941 Pirnie 98-10 X 2,494,260 1/1950 Osmond 126360 3,232,206 2/1966 Kennedy 98108 ROBERT A. OLEARY, Primary Examiner.

M. A. ANTONAKAS, Assistant Examiner. 

